The strategy of building a multi MW, accelerator based spallation neutron source as the next generation neutron facility for Europe has been validated by the successful commissioning and operation of the SNS in the US (now operating close to 1 MW beam power) and the JPARC facility in Japan. However, since the original baseline design of ESSwas completed in 2002, the underlying technology has advanced and some considerable experience has been gathered from these new facilities. Hence as Europe prepares for the construction of ESS, the time is ripe to learn from ongoing experience and define the development areas which would allow the ESSto take the most advantage from recent advances in technology while maintaining a reliable, low risk, design.

The goal of the ESS-Bilbao Initiative Workshop, organized by the ESS-Bilbao consortium, was to assess the current challenges facing multi-MW spallation sources and, taking into account synergies with other international projects of a similar nature, outline a road map for a collaborative Research and Development program that would enable Europe to meet these challenges for the timely construction of ESS.

The workshop, which took place the 16 – 18 March in Bilbao brought together more than 160 experts from across the world, leaders in the fields of high power proton accelerators, beam dynamics and targets, in a format and infrastructure that promoted open discussion, while maintaining the focus of documenting clear recommendations for future collaborative R&D efforts. Now we present the conclussions.

The values in the table are proposed as the basis for a feasibility assessment of the ESS linac components in the following sections. In comparison to the originally proposed design (5 MW, 1 GeV, 150 mA, 16.7 Hz) the parameters have been modified in order to simplify the linac design and to increase reliability. In essence the current has been decreased and the final energy has been increased, keeping the footprint of the accelerator the same. It should be stressed that all the linac components are essentially the same, whether the linac delivers lower energy beams with higher beam currents, or higher energy beams with lower beam current. However, as will be explained in the following the latter option can considerably ease the demands on beam physics and contribute to more reliable accelerator design.

Due to the strategic biogeographical position of the Basque Country, placed between the Eurosiberian and Mediterranean systems, the climatic gradient that runs from the coast towards the interior, together with differences in altitude of more than 1000 m, there is a great wealth of flora and fauna. In this way, more than 3000 species of plants and almost 40 invertebrates live in the extensive network of natural spaces in the Basque Country, a land where nature coexists in harmony with human beings.

Environmental management

Through the Environment and Territorial Planning Department, the public administration of the Basque Country develops and manages one of the most advanced environmental protection and conservation policies in Europe. Based on a strategy of long-term sustainable development (2002-2020 Basque Sustainable Development Strategy) the struggle against climate change, the preservation of biodiversity and the prevention and control of contamination, are just a few of its areas of activity. There is a specific action plan for each area (2007-2010 Basque Plan to Fight against Climate Change; 2009-2014 Biodiversity Strategy; etc.), which aim to achieve continuous environmental improvement. The development of these policies has been strengthened through the firm support given to environmental R&D&I over recent years in the Basque Country. The BC3 (Basque Centre for Climate Change), the CIC energyGUNE (Cooperative Research Centre in Renewable Energies), the Torre Madariaga Biodiversity Observatory Unit and the Environmental Economics Unit (University of the Basque Country) are a few of the research centres whose work helps to raise an awareness of environmental problems and more efficient solutions to help in their eradication.

Broad plains, mountain ranges, green woods, spectacular cliffs, abundant wetlands and marshes and relaxing beaches. Lovers of natural spaces have a great deal to discover in the Basque Country. The diversity and beauty of its landscapes have been preserved not only in its protected areas but in a large part of the territory. Visitors can enjoy natural spaces and ecosystems located very near urban centres and cities. In the Basque Country, nature is just a stone’s throw away from civilization.

Protection and conservation

The Basque Country has nine natural parks, five protected biotopes and a biosphere reserve, Urdaibai, where the cliffs and beaches of the coast and the reserve’s woods, wetlands and inland rivers make up the greatest diversity of landscapes and ecological resources in our territory. In total, 14% of the surface area of the Basque Country is protected in accordance with one of these schemes (above the European average of 12.3%). Additionally, a technical design proposal has been drawn up for a network of ecological corridors to ensure the viability of the populations of flora and fauna of the Basque Country. On the other hand, it is interesting to note that more than 20% of the surface area of the Basque Country is included in the European Natura 2000 network.

Sea, rivers, coastline and beaches

The 252 km of Basque coastline is one of the most important tourist destinations thanks to the natural beauty of its surroundings, where beaches of fine sand are interspersed with steep cliffs, river estuaries and a number of wetlands and marshes of great ecological interest. Inland, you can discover a large number of recreational and leisure areas by rivers and reservoirs, some of which represent veritable inland seas which are bound to surprise you. The Cantabrian sea is home to a large number of marine mammals and one can see a wide variety of cetaceans (dolphins, fin whales, sperm whales, etc.) during the voyage of the Bilbao-Portsmouth ferry, which offers crash courses on marine fauna.

Since some years ago, the nanomaterials and nanoscience is the “new wave” in science. The interesting in this subject is provided by the extrange behaviour of the physics in this size. Things like corpuscle-wave duality, tunneling effect, uncertainty principle and so on are lately very common in amazing news about science. The real interest in this science, in this nanoparticles that behave in such a way, is that we could controlate the materials in a very precise way. We could be able to create magnetic nanoparticles who go to an specifically part of the body (a sick part, like tumor) carried there by a vector (biologic marker), and then, observe exactly where is the sickness, how is it, and maybe destroy it with magnetic fields.

Therefore, is very important to unveil the real structure and composition of materials made of nanoparticles, like the thickness of a nanostructure layer of a semiconductor (in order to make a led, for example). Neutrons suffer bothelastic scattering and inelastic scattering with the nucleus. With the first, we can uncover the arrangement and the degree of order in the solid. With the latter, we can understand the movements and difussion inside the nanostructure. But another characteristic of the neutrons is the magnetic moment (represented by the spin). This magnetic moment can interact with the magnetic moment of the particles we are studying, providing information about its magnetics domains, polarization and so on. Very interesting properties to develop magnetic devices.

The small angle neutron scattering(SANS), in wich the detectors are far from the sample to study, and therefore the detection is in small angle, is very used to detect nanoparticles in some sample. This SANS studies in magnetic materials have been used to detect the core and the shell nanoparticles structure in ferrofluids, to analyze coercivity in magnetics alloys and magnetic correlations with the external field.

Also in inelastic experiments, neutrons are revealing interesting (but yet scarce) results in subjects like acoustic phonons in solid state, variations in the propagation of magnetic waves (spin waves) produced by temperature changes,… This experiments also provides the possibility to achieve interesting results is the spin neutron ecco.

This is just a simple overview on neutron scattering experiments, but it’s clear neutron techniques are essential nowadays, because allow us to investigate and unveil the core composition and shell structure of nanomaterials, with incredible applications at present days. The ESS facility will provide a powerful installations to improve knowledge and growing of nanoparticles and nanoscience, avoiding some difficulties present now in this subjects.

ESS BILBAO

The ESS-Bilbao consortium is an entity created to promote the candidature of Bilbao for the ESS (European Spallation Source).
The Spanish effort is conducted through the Spanish Ministry of Science and Innovation, which develops and carries out government policy in the promotion and overall coordination of scientific research and technological development. The Basque effort is managed through the Department of Industry, Commerce and Tourism and the Education, Universities, and Research Department, which is responsible for proposing and carrying out scientific research and technological innovation policies.